Building the arena had many chapters

HARRY FISHER, THE MORNING CALL

This is what the PPL Center site looked like on March 7, 2013. The Dime Bank building, incorporated as part of the arena complex, is the standalone building on the right.

This is what the PPL Center site looked like on March 7, 2013. The Dime Bank building, incorporated as part of the arena complex, is the standalone building on the right. (HARRY FISHER, THE MORNING CALL)

The raising up of Allentown's new arena began with a tearing down of the old.

In February 2012, after a city authority bought an entire block at Seventh and Hamilton streets, demolition crews descended, knocking down 27 buildings over 5.3 acres of center city real estate.

A block of mostly low-end retail stores was reduced to rubble and carted away.

What followed was a race against the elements, the uncertainty of litigation and a demanding fall 2014 opening deadline.

"Every job has its complexities and challenges," said Greg Butz, president and CEO of Alvin H. Butz Inc., Allentown, the construction manager on the site. "With the arena, the schedule was very much a living and breathing document."

To start, bulldozers dug out and trucks hauled away 110,000 cubic yards of dirt, turning the arena's footprint into a three-story hole in the ground, that when it rained, turned to mud. The walls of the hole were shored up along Hamilton, Linden and Eighth streets.

Then litigation filed by a coalition of suburban municipalities upset over the use of their residents' earned income taxes threatened to derail the project entirely, throwing the construction schedule into limbo. A June settlement cleared the way for activity to resume in earnest.

In August, workers began pouring the foundation, made up of 1,689 mini-pilings driven deep into the bedrock to protect the building against sinkholes. Designers thought the pilings would go 45 feet into the ground. In the end, the protective foundation anchors would average 65 feet.

By December, workers had turned to shoring up the historic Dime Savings Bank, a nearly century-old structure architects planned to incorporate into the state-of-the-art arena complex. Again, there were surprises.

The bank's foundation ended many feet shy of the floor of the arena, forcing workers to hand-dig 44 3-to-4-foot wide pits beneath the structure that would be filled with concrete and steel to shore it up.

Meanwhile, workers began pouring cement for the 120-space VIP parking area that would be contained beneath the arena's south side, displacing a section of the dirt floor.

In April 2013, with underground tanks and plumbing in the ground, steel beams, fabricated by Amthor Steel in Erie, began arriving in Allentown and rising from the floor of the future arena.

It was not easy getting the beams and much of the rest of the construction material into the city, through its narrow, traffic-clogged streets.

For the next eight months, workers raised the arena complex skeleton, starting with the Renaissance Allentown Hotel on the east side. They then moved to the north side, followed by the Hamilton Street Lehigh Valley Health Network office building on the south side, before completing the rest of the complex.

The roof was a feat of engineering, with seven, massive 24-foot tall trusses as long as 236 feet. The first truss, which took 46 hours to lower into place, was completed in late September. Using trusses to span the ice floor allows for unobstructed views of the action.

"Imagine erecting a 300-ton steel truss in the middle of a city block and within the walls of the arena," Butz said.

At the same time, from May to November 2013, workers poured 27,000 cubic yards of cement, laying the floor of the arena and its attached hotel and office complex. Precast concrete risers — the floor of the seating area in the arena bowl — began being lowered in place in July, finishing up in January of this year.

Workers outside the complex were installing brick panels as the exterior facade and securing them to the steel beams erected earlier by steelworkers. The panels were made by Eastern Exteriors, Bethlehem.

Heavy-duty restoration work on the Dime Bank began in August. The building was in disrepair and its exterior bricks had to be painstakingly removed, while its frame had to be reinforced with steel and its facade rebuilt using modern construction techniques.

Other workers began to "rough-in" the interior of the arena, including its Kid Zone, concourse restrooms and bars, as well as its suites, club bar, press box and coaches rooms.

In September 2013, contractors began installing the equipment that would keep the arena cool in summer and snug on cold winter nights. Chillers, pumps and boilers were brought in as electrical workers strung miles of cable through the facility.

The roof went on in November, a high-tech sandwich of materials designed to be light, resilient and strong. By the end of 2013 the arena complex was connected to its permanent power source.

A brutal winter, with some of the coldest, snowiest days in years, didn't make finishing on time easy.

"We had to get very creative with the schedule during the winter and move to indoor tasks," Butz said.

With the roof on, work could start on the arena's central feature, its ice floor. Workers began to excavate the floor in January, finishing the job in mid-April with the final pour of cement.

The 17,000-square-foot floor includes 4 inches of rigid insulation over 8 inches of sand embedded with piping under a 12-inch structural concrete slab. It needed 20,000 square feet of wire mesh and 15 tons of iron rebar in addition to 14 miles of underground piping and 315 square feet of concrete, the equivalent of 30 trucks' worth.

To guarantee a flat floor, workers used laser-guided machinery to level it to regulation National Hockey League specifications. The facility has more than 100 floor inserts to accommodate events such as basketball, tennis and concerts.

Internal building systems, such as the fire alarms, were fully tested and the finishing touch, 8,500 seats, were installed, starting in July.